1. Field of the Invention
The present invention relates to an electronic component, and more particularly to a contact terminal which provides a connection between two different parts such as a battery pack of a portable electronic device and various cables.
2. Description of the Related Art
In general, portable terminals house detachable battery packs and devices which require electrical connections between two different components such as a communication cable and a memory card socket. A docking cradle for a portable terminal further include various types of contact terminals.
For example, a portable terminal having a detachable battery pack includes a connection piece fixed into the battery pack, and a contact terminal with a plate spring called a C-clip which is disposed in a body of the portable terminal. When the battery pack is coupled to the body of the portable terminal, the connection piece of the battery pack pushes the contact terminal of the terminal body by a degree to maintain a stable connection state. A known contact terminal uses a plate spring and is provided to a connection structure of an above-mentioned battery pack or a connector of a communication cable.
Meanwhile, a portable terminal having a near field communication (NFC) function is becoming popular where various cards such as a traffic card, a user authentication security card, and a credit card are approved or authenticated through near field communication (NFC). To this end, a portable terminal utilizes a separate antenna for performing the NFC function which may be installed in a battery cover. Moreover, an antenna or a coil for wireless charging is installed in the battery cover, in which case a contact terminal needs to be installed to connect the antenna or coil to a circuit installed within the terminal body.
FIGS. 1 and 2 illustrate a conventional contact terminal 30, which is manufactured to have an ‘S’-like shape by bending a metallic plate, and it has a pair of protruding contact portions 33a and 33b at upper and lower ends thereof. When the contact terminal 30 is installed within a housing 11 of the portable terminal, one of the contact portions 33a and 33b contacts a circuit board 13 installed within the housing 11, and the other contact a battery pack contacts a connection piece 23. Although FIG. 2 does not illustrate a deformed shape of the contact terminal 30, the contact terminal 30 is substantially compressed when the contact portions 33a and 33b contact surfaces of the circuit board 13 and the connection piece 23. As such, a resilient force caused by compression of the contact terminal 30 is intensively accumulated mainly at curved portions 35a and 35b of the contact terminal 30.
Such a conventional C-clip type contact terminal has a structure where a load is concentrated to curved portions, thus must be supported by a separate resilient body 37 such as silicon or urethane to secure durability. That is, the C-clip is supported by the resilient member 37 as a load continues to be applied to the C-clip but it may be permanently deformed when an excessive load is applied thereto. Also, as a predetermined area of the C-clip is exposed to external to provide a stable connection, an outer aesthetic appearance of the portable terminal is suffered. Further, since the C-clip is manufactured by bending a plate, a sharp portion may be formed at a side thereof, in which case a user may be injured or an external environment may be damaged.
FIGS. 3 and 4 illustrate a general pogo pin 40 and a structure where two different parts 13 and 23 are connected to each other via the pogo pin 40. A portion of a contact pin 43 is received within a tube 41 of the pogo pin 40, and the contact pin 43 linearly reciprocates in a direction where the contact pin 43 is inserted into or extracted from the tube 41. Then, a coil spring 45 is accommodated in the contact pin 43, and an end of the coil spring 45 protrudes toward one end of the contact pin 43 to be supported by the tube 41. The coil spring 45 provides a resilient force applied in a direction where the contact pin 43 is extracted from the tube 41.
The pogo pin 40 is installed in a portable terminal with one end of the tube 41 contacting the circuit board 13 of the portable terminal and an opposite end of the contact pin 43 protruding to the outside of the portable terminal Then, a separate C-clip 19 is disposed between the circuit board 13 and the tube 41 to stably connect the pogo pin 40 to the circuit board 13. When the pogo pin 40 is utilized as a contact terminal for connection of a battery pack, if the battery pack is coupled to a portable terminal, the contact piece 23 of the battery pack pushes an end of the contact pin 43 which in turn causes the contact pin 23 retreats into the tube 41. Then, a resilient force accumulated while the coil spring 45 is being compressed and stably maintains the contact pin 43 to be connected to the contact piece 23 and the tube 41 to be connected to the circuit board 13.
Although the pogo pin has a higher quality and provide a better outer appearance than that of a plate spring, the pogo pin cost more, thereby increasing the manufacturing costs of the portable terminal. Further, noise is generated by relative movement between components of the pogo pin itself which is a drawback and undesirable during operation.